User Tag List

Page 2 of 2 FirstFirst 12
Results 11 to 19 of 19
  1. #11
    Big Traveler
    Join Date
    Sep 2020
    Location
    Thunder Bay, Ontario, Canada
    Posts
    1,890
    Mentioned
    20 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Rabbit View Post
    Unfortunately it is acceptable per CSA for the RV industry, which the US accepts, but braided hose/tubing is not per standard in US
    The braided soft hose has an ASTM rating, American Society for Testing and Materials.

    Just FYI, but there is some suggestion out there that GD is using a different soft hose in newer units that has an ID closer to pex so leaks are less frequent. Still using pex clamps on soft hose which is a problem, but hey...its a bit better!
    Last edited by Scott'n'Wendy; 12-31-2022 at 03:04 PM.
    2018 Dodge 3500 6.7 Cummins SRW w/Aisin
    2021 Reflection 303RLS
    New to RV'ing since 1997

  2. #12
    Site Sponsor
    Join Date
    Jul 2021
    Posts
    388
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    True PEX tubing/pipe is dimensionally CTS (copper tube size) which is the size of virtually all water service line pipes and fittings approved for water distribution and plumbing systems as set by AWWA standards (American Water Works Assn), this includes Sharkbite brand. Braided pipe has an ASTM standard, but that’s not a guarantee it’s compatible with or equal to CTS specs. That’s where the compatibility problem stems. ASTM only means “all” tubing made to that spec will be similar in dimension, material and other characteristics, but doesn’t mean it will be compatible with CTS fittings.

    The braided tubing in my GD 3100RD is marked CSA, a Canadian Standard which makes the tubing permissible for use in RV plumbing. But it could never be used in building construction, for instance. Virtually all plumbing fittings intended for building construction are made to AWWA standards, not CSA, although some ASTM specs are compatible with AWWA.

    The disconnect is PEX and braided tubing are not the same animal.

    Barbed fittings are not AWWA. PEX are. I have no idea how or why braided tubing became acceptable in RVs, so I’ll stop without suggesting it’s not acceptable. According to CSA it is. But I stand by my original advice that Sharkbites and similar o-ring sealed fittings are not reliable on braided tubing. Use barbed fittings with a suitable pipe clamp.

  3. #13
    Left The Driveway
    Join Date
    Aug 2021
    Posts
    5
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The thing that bothers me is that I can't believe the cost savings of braided tubing is really that much compared to PEX for the lengths we have in a RV. Particularly when one compares this to the purchase price.

    I made my dissatisfaction clear in the recent survey I received as a result of my last GD purchase (2022 22RBE). In the survey response I marked down trailer quality and noted in the comments this was entirely due to use of braided tubing and not PEX (happy in all other respects). The irony is that I also responded quality was the #1 priority in my selection process. At the time I purchased I didn't know enough to look for PEX. I also put in the comments that I would have been willing to pay a little more for PEX. Given GD can stand behind the CSA approval, I doubt that will change the reality though

    Again, I maintain that even though it is an industry standard that doesn't make it a good design choice ... as others have confirmed.

  4. #14
    Long Hauler huntindog's Avatar
    Join Date
    Nov 2017
    Posts
    2,175
    Mentioned
    33 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by TravelHabit View Post
    The thing that bothers me is that I can't believe the cost savings of braided tubing is really that much compared to PEX for the lengths we have in a RV. Particularly when one compares this to the purchase price.

    I made my dissatisfaction clear in the recent survey I received as a result of my last GD purchase (2022 22RBE). In the survey response I marked down trailer quality and noted in the comments this was entirely due to use of braided tubing and not PEX (happy in all other respects). The irony is that I also responded quality was the #1 priority in my selection process. At the time I purchased I didn't know enough to look for PEX. I also put in the comments that I would have been willing to pay a little more for PEX. Given GD can stand behind the CSA approval, I doubt that will change the reality though

    Again, I maintain that even though it is an industry standard that doesn't make it a good design choice ... as others have confirmed.
    I think the cost savings is in labor. Having flexible hose to the termination points speeds up production a lot. 100% pex plumbing means pretty precise measuring and cutting/clamping as there is limited amount of flex to be had.
    2021 398M Full Body Paint 8k axles. LRH tires. Disc brakes.
    Two bathrooms, no waiting 155 fresh, 104 black, 104 grey 1860 watts solar.
    800AH BattleBorn Batteries No campgrounds 100% boondocking
    2020 Silverado High Country 3500 dually crewcab Duramax Allison

  5. #15
    Left The Driveway
    Join Date
    Aug 2021
    Posts
    5
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Perhaps, but even then it can't be that much. I noted the GD assembly techniques for braided tube appear to use PEX crimpers and similar tools (which is the primary source of the problem in first place!!). That is, the labor time for connections is probably the same for braided or PEX. Moreover, for each model, the lengths could be determined once and and all future installs would be identical (or close enough). Plumbing wise, it would actually be much easier than typical home construction where each PEX run is more or less custom. Agreed, there is less flex but can that really drive labor cost for an assembly line?

    On the other hand, there clearly is a cost savings that GD sees. Its certainly combination of engineering design, material, and labor. I recall when I was working as an engineer and our NASA customer asked for a proposal for a seeming minor change... they were shocked by the amount we proposed. In that case the price was almost completely due to the NRE associated with drawing changes that rippled through the design causing significant hours of engineering time for those updates. The part cost and manufacturing time was essentially the same. That said though, from what I understand GD does not require the same detailed drawings since much is left to the individual builders due to semi-custom manufacturing methods.

  6. #16
    Long Hauler huntindog's Avatar
    Join Date
    Nov 2017
    Posts
    2,175
    Mentioned
    33 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by TravelHabit View Post
    Perhaps, but even then it can't be that much. I noted the GD assembly techniques for braided tube appear to use PEX crimpers and similar tools (which is the primary source of the problem in first place!!). That is, the labor time for connections is probably the same for braided or PEX. Moreover, for each model, the lengths could be determined once and and all future installs would be identical (or close enough). Plumbing wise, it would actually be much easier than typical home construction where each PEX run is more or less custom. Agreed, there is less flex but can that really drive labor cost for an assembly line?

    On the other hand, there clearly is a cost savings that GD sees. Its certainly combination of engineering design, material, and labor. I recall when I was working as an engineer and our NASA customer asked for a proposal for a seeming minor change... they were shocked by the amount we proposed. In that case the price was almost completely due to the NRE associated with drawing changes that rippled through the design causing significant hours of engineering time for those updates. The part cost and manufacturing time was essentially the same. That said though, from what I understand GD does not require the same detailed drawings since much is left to the individual builders due to semi-custom manufacturing methods.
    I got to tour the Sabre factory when I bought one of their models. It did not run like a automobile factory with a seperate line for each model. They had one line that produced all of their models. They did try to bunch like models together , but it wasn't always possible. So things like pex were just taken from bulk spools as needed.
    They simply did not produce enough units to justify each model having it's own line. I am betting that GD operates pretty much the same.... This also explains a lot of the haphazard construction we see.
    2021 398M Full Body Paint 8k axles. LRH tires. Disc brakes.
    Two bathrooms, no waiting 155 fresh, 104 black, 104 grey 1860 watts solar.
    800AH BattleBorn Batteries No campgrounds 100% boondocking
    2020 Silverado High Country 3500 dually crewcab Duramax Allison

  7. #17
    Site Sponsor Steven@147's Avatar
    Join Date
    May 2017
    Location
    Texas Fulltimers
    Posts
    2,551
    Mentioned
    32 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by huntindog View Post
    I think the cost savings is in labor. Having flexible hose to the termination points speeds up production a lot. 100% pex plumbing means pretty precise measuring and cutting/clamping as there is limited amount of flex to be had.
    A lot to this, and more use of 90* elbows and clamps since pex doesn't bend too well. Like as said more precise measuring of pex tubing lengths and more thought put into installation. I don't think it would take that much more time for labor to use all pex using experienced pex plumbing installers and seeing as how GD has pretty much separate manufacturing lines like for Momentum / Solitude, Reflections, Imagine / Transend etc. but the factory may think it does. But then again like I said "experienced pex plumbing installers" , not something I think RV manufacturing lines care much about, and quality work, just good enough is ok with them, that's the sad part..

    Right now I'm fixing another flex to pex leak, from T's behind the basement wall, over and up into the bathroom and connection to the dual sinks and faucets. And if am going to get in there I'll do both cold and hot lines.
    Steve & Tami Cass - Escapee's, FMCA Members, Texas Fulltimers Since July 2020
    2019 Solitude 3350RL S-Class, 2018 Ram 3500 DRW, Laramie Longhorn, B&W Companion, Texas Class A Non-CDL Drivers License
    Sharing the Fulltime Lifestyle - www.youtube.com/@tsrvadventures3219/videos, Nonprofit Channel

  8. #18
    Long Hauler huntindog's Avatar
    Join Date
    Nov 2017
    Posts
    2,175
    Mentioned
    33 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Steven@147 View Post
    A lot to this, and more use of 90* elbows and clamps since pex doesn't bend too well. Like as said more precise measuring of pex tubing lengths and more thought put into installation. I don't think it would take that much more time for labor to use all pex using experienced pex plumbing installers and seeing as how GD has pretty much separate manufacturing lines like for Momentum / Solitude, Reflections, Imagine / Transend etc. but the factory may think it does. But then again like I said "experienced pex plumbing installers" , not something I think RV manufacturing lines care much about, and quality work, just good enough is ok with them, that's the sad part..

    Right now I'm fixing another flex to pex leak, from T's behind the basement wall, over and up into the bathroom and connection to the dual sinks and faucets. And if am going to get in there I'll do both cold and hot lines.
    I am aware that GD has seperate lines for Momentums, Solitudes etc. But how many different models share those lines? The RV industry does not use any robots or have a system where the right part arrives at the right time to be installed like the automotive industry does. It would be far to expensive at the volumes they produce.
    2021 398M Full Body Paint 8k axles. LRH tires. Disc brakes.
    Two bathrooms, no waiting 155 fresh, 104 black, 104 grey 1860 watts solar.
    800AH BattleBorn Batteries No campgrounds 100% boondocking
    2020 Silverado High Country 3500 dually crewcab Duramax Allison

  9. #19
    Setting Up Camp
    Join Date
    Jun 2020
    Location
    S/E Texas
    Posts
    18
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Just got back from a week long spring break trip with my family. Second morning of the trip we had water coming out from under my shower. (2021 Transcend Xplor) Got the rig home, and put it in my shop. After pulling the shower out, I found plastic pex fittings with vinyl hose. I made the decision to repipe the whole trailer with PEX. Piss on that vinyl crap. I also had to remove almost all of my insulation under the trailer. We are in a warm climate, so Im not too worried about the insulation. I dont plan on putting it back.

    anyway, I started the repipe yesterday, and have a pretty good handle on it in just a few hours. It goes pretty fast. One thing is for sure, when I am done I will have closed up most of the rodent entry points! I did not realize the left so many openings for the little buggers!

Page 2 of 2 FirstFirst 12

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

DISCLAIMER:This website is not affiliated with or endorsed by Grand Design RV, LLC or any of its affiliates. This is an independent site.